<meta charset="UTF-8">
<style>
    *{margin:0px;padding:0px;}
    body{
        background:url(https://img2.baidu.com/it/u=57628836,2989936375&fm=253&fmt=auto&app=138&f=JPEG?w=767&h=500);
        background-size:cover;
    }
    .login_div{
        background:rgba(0,0,0,0.3);
        position:absolute;
        color:white;
        left:50%;
        top:20%;
        margin-left:-150px;
        width:300px;
        height:290px;
        padding:20px;
        border: 1px solid #ccc;
    }
    .company_name{
        font-size:18px;
        text-align: center;
        margin-top:10px;
        margin-bottom: 10px;
    }
    .input_div{
        margin-top:20px;
        margin-bottom:20px;
        text-align: center;
    }
    input{
        width:260px;
        height:36px;
        outline: none;
        padding-left:5px;
    }
    .btn{
        width:260px;
        height:36px;
        line-height: 36px;
        background:orange;
        margin-top:20px;
        text-align: center;
        border-radius: 3px;
        margin-left:auto;
        margin-right:auto;
    }
</style>
<div class="login_div">
  <div>注册:</div>
  <div class="company_name">新凌通信物料管理系统</div>
  <div class="input_div">
    <input id="u" placeholder="用户名" /></div>
  <div class="input_div">
    <input id="p" placeholder="密码" type="password" /></div>
  <div class="input_div">
    <input id="p2" placeholder="确认密码" type="password" /></div>
  <div id="b" class="btn" onclick="reg()">注册</div>
</div>
<script>
    function reg(){
        var req = new XMLHttpRequest();
        req.open("post","/sysuser_reg");
        req.setRequestHeader("Content-Type",
            "application/json;charset=utf-8")
        var data = {
            username:u.value,
            password:p.value
        }
        req.send(JSON.stringify(data));
        req.onreadystatechange = function(){
            if(req.readyState==4&&
            req.status==200){
                alert(req.responseText);
            }
        }
    }
</script>